This invention relates to a steering mechanism enabling a jet boat operator to steer the boat from the pilot seat when the boat is driven alternatively by a trolling motor.
It is desirable for a boat owner to be able to operate his boat for both high speed recreation, e.g., water skiing, and low speed recreation, e.g., trolling for fish. The high power engine necessary for high speed recreation is not desirable for slow speed use and it is common to fit such a boat with an auxiliary small motor (referred to as a trolling motor) that operates more smoothly, more efficiently and more quietly at speeds, e.g., below 10 miles per hour.
As particularly relates to jet boats when driven by the faster jet motor, steering is accomplished from a pilot seat toward the front of the boat. Upon shifting to the trolling motor, the driver must relocate to the rear of the boat where the smaller trolling motor is steered directly by pivoting the motor.
It is an objective of the present invention to provide a linkage or coupling from the steering mechanism for the jet motor to the trolling motor to enable steering of the trolling motor from the pilot seat via the jet boat steering wheel.
A jet boat operates in general by pumping water out the rear of the boat through a steering nozzle. Steering of the boat is accomplished by pivoting the nozzle from side to side and control over such pivoting is achieved by a coupling that extends from the pilot station (including a pilot chair and steering wheel) at the front of the boat, to the steering nozzle at the rear of the boat. The steering wheel is turned as in a vehicle and that turning is converted by the coupling to pivotal side-to-side movement of the steering nozzle.
A small outboard motor (trolling motor) mounted on the rear of the boat includes a motor mount that is rigidly secured to the rear of the boat. The motor itself is pivotally mounted to the motor mount in that the motor can be pivoted about a vertical axis relative to the motor mount. A drive propellor is extended from the motor into the water at the rear of the boat and is directionally controlled by pivoting of the motor. Typically a handle extended forwardly from the motor is gripped by an operator sitting just forward of the motor mount and by moving the handle in a horizontal arc about the vertical axis, the operator controls fine steering of the boat when propelled by the trolling motor.
The inventor determined that if he could couple the steering motion of the steering nozzle to the trolling motor, he could similarly control the steering of the trolling motor, i.e., via the steering wheel at the pilot station.
Steering is achieved by pivotal action for both the steering nozzle of the jet boat and the trolling motor. However, there is no practical way to generate a rigid link between the steering nozzle and the trolling motor. Accordingly, the inventor derived a concept or (a) converting the pivotal motion of the steering nozzle to linear motion, (b) transmitting the linear motion via a push/pull control cable to the trolling motor and (c) converting the linear motion back to pivotal motion as required for corresponding pivotal motion of the trolling motor.
The pivotal motion of the steering nozzle encompasses the coupling mechanism between the steering wheel and the steering nozzle. For example, a shaft is sometimes used to actuate pivoting of the nozzle. The shaft restrictively turns about its axis, back and forth, within an angular range of, e.g., 90 degrees. In response to such back and forth turning, the steering nozzle is correspondingly pivoted from side to side to effect turning. An arm clamped to the shaft will pivot within the same angular range, e.g., 90 degrees.
Alternatively, the direct pivotal action of the steering nozzle may be used by fixing an arm to the nozzle so that it pivots in direct relation to the steering nozzle.
It is here explained that different makes of jet boats present different structures that have to be accommodated. A suitable pivotal arm may be a component of the existing structure but likely one needs to be generated, e.g., by fixing an arm member to a movable component, the movable component either generating the steering motion of the steering nozzle, the movable component being the steering nozzle itself or the movable component being responsive to the steering motion of the steering nozzle. Further, with each make and model of a jet boat, the pivotal arm to be created must be located so as to avoid interference with other components of the boat as it is pivoted through a full range of steering motion.
For the preferred embodiment of the invention, it is desirable for the distal end of the pivotal arm to have a throw distance (a linear distance measured from extreme clockwise to extreme counter clockwise locations of the distal end) of about six inches. The pivotal motion of the arm is converted to linear motion (as much as six inches) that is transmitted to the location of the trolling motor via a push/pull control cable assembly.
The push/pull control cable assembly as utilized in the preferred embodiment of this invention includes an elongate flexible sleeve and a flexible slide member that slides through the sleeve and is connected at each end to a rigid rod which projects from the sleeve ends. Whereas the body of the cable is flexible and can be formed into a variety of curved shapes through which the slide member readily slides, the ends defined by the rigid rods produce a linear force as extended from the sleeve. Such a control cable is available from the Cablecraft Division of Tuthill Corporation in Tacoma, Wash. and is advertised for transmitting linear motion applicable to throttles, clutches, latches, hitches, chokes, shifter valves, dumps and PTO (power take off).
The sleeve end of the cable assembly is fixedly mounted to the boat proximal to the distal end of the pivot arm with the rod end pivotally attached to the distal end of the pivot arm. Thus, pivoting of the pivot arm pulls and pushes the rigid rod into and out of the sleeve. The slidable member within the major length of the sleeve correspondingly slides back and forth within the sleeve and forces the rigid rod at the opposite end into and out of that sleeve end. (Into and out of the sleeve end has reference only to the exposed portion of the rod end as an inner portion of the rod end is retained inside the sleeve throughout the in and out sliding motion.) The cable length can be made to whatever length is needed to run the cable from its end location proximal to the pivot arm to the location of the trolling motor at the back of the boat.
The trolling motor as desired is steered by pivoting the motor relative to the motor mount. A bracket, arm or brace, existing or added or even part of the motor housing, is established as the desired pivotal connection for the push/pull rod based on the desired pivoting of the motor to achieve full left to full right turning of the motor. That is, assuming the rod will movably project from the sleeve and as much as six inches, such must be matched to the desired throw distance of the established point of pivotal connection, i.e., when pivoting the motor from full right to full left turn. This may be accomplished simply by using the same length of pivot arm at both ends of the cable to achieve a similar angle of pivoting as between the steering nozzle and trolling motor. In some cases, however, the angle of pivoting may differ, e.g., the steering nozzle at 90 degree pivoting may be best matched to a 110 degree pivoting of the motor. Different pivot arm lengths will accommodate such differences.
The above explanations will be more fully understood upon reference to the following detailed description of the preferred embodiment.